Recently, a rechargeable secondary battery has been widely used as an energy source of a wireless mobile device. In addition, the secondary battery has been spotlighted as a power source of an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (Plug-In HEV), and the like, that have been suggested as a scheme for solving air pollution of an existing gasoline vehicle, diesel vehicle, or the like, using fossil fuel.
Small-sized mobile devices use one to four battery cells per one device. In contrast, middle or large-sized devices such as a vehicle, or the like, require high output and large capacity, such that they use a middle or large-sized battery module in which a plurality of battery cells are electrically connected to each other.
Since it is preferable that the middle or large-sized battery module is manufactured to have a size and weight as small as possible, it may be integrated at a high degree of integration. In addition, a prismatic battery, a pouch type battery, or the like, having weight small as compared with capacity has been mainly used as a battery cell of the middle or large-sized battery module. Particularly, the pouch type battery using an aluminum laminate sheet, or the like, as an exterior member has been recently interested mainly due to advantages such as small weight, a low manufacturing cost, easy deformation, and the like.
Since the battery cells configuring the middle or large-sized are configured of the rechargeable secondary batteries, the high output and large capacity secondary battery as described above generates a large amount of heat in a process in which it is charged or discharged. Particularly, since a surface of a laminate sheet of the pouch type battery widely used in the battery module is coated with a polymer material having low thermal conductivity, it is difficult to effectively decrease a temperature of all of the battery cells.
In the related art (US 2011-0052960), a secondary battery module including a plurality of cooling channels disposed in parallel with each other so as to face each other and closed so that a heat transfer medium may flow therein; a plurality of unit batteries disposed between the plurality of cooling channels; supply channels supplying the heat transfer medium to the cooling channels; discharge channels discharging the heat transfer medium from the cooling channels; and spacers disposed in the cooling channels to maintain intervals in the cooling channels has been disclosed.
However, in the related art, the plurality of cooling channels and the plurality of unit batteries are not closely adhered to each other, such that thermal conductivity is decreased.
Further, it is obvious that when the thermal conductivity is decreased, cooling efficiency is decreased.
Therefore, there is a need to develop a battery module including a heat exchange member capable of further improving the thermal conductivity.